Known methods for converting a halomethyl compound to a hydroxymethyl compound generally use a hydrolysis of the corresponding iodomethyl compound.
Now, the present inventors have found that this conversion proceeds with oxygenation more economically and with a higher yield and as a result of this discovery they were led to this invention. They confirmed further that this reaction goes satisfactorily with an oxidizing agent even with diluted molecular oxygen, e.g., air.